A revision of the genus Camptocercus (Anomopoda, Chydoridae, Aloninae)

The genus Camptocercus is revised. Camptocercus streletskayae sp. n. is described from East Siberia. The status of other species is discussed on the basis of a standard set of morphological features, including the structure of the cephalic region, the post-abdomen and post-abdominal claw, the dorsal keel, denticles at the ventro-posterior angle of valve, and setae on the inner distal lobe of limb I. Geographical distribution of species of this genus is discussed. A key to the species of this genus is composed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Pleuroxus denticulatus (Crustacea: Anomopoda: Chydoridae) a new invader in the Danube Basin

Pleuroxus denticulatus Birge, 1879 is a new invader from Western to Central Europe. Its occurrence in a Danube inundation (Slovak region) probably corresponds with the junction of the Danube and Rhine Rivers. The species was found among ‘the hard macrophytes’ of flowing arms and artificial ponds. A large variability was recorded in the number of valval denticles and in postabdominal denticulation. It is evident that part of the N. American populations is different from European populations. P. denticulatus seems to represent two sibling species. Both are characterised by an angular distal postabdominal corner, bearing 3–4 denticles, and by valval denticles on the postero-ventral corner. This revised version was published online in July 2006 with corrections to the Cover Date.     

Sensory and glandular equipment of the trunk limbs of the Chydoridae and Macrothricidae (Crustacea: Anomopoda)

Each of the five pairs of trunk limbs of theChydoridae and Macrothricidae contains one or severalcuticular pores, some of which connect to glands whichsecrete to the filter chamber. They are situated in afixed or a variable position, usually on the endite ofthe limb.Limbs 2 to 5 are also equipped with small sensoryorgans which may be apically perforated or not.Relatively large, perforated sensilla, often with aspecies- or genus-specific morphology occur on theendites of P3, P4 and sometimes on P5; unperforatedpapilliform and batilliform sensilla occur in variouspositions on P2, P3, and P4. In the Macrothrixlaticornis-group, three of the six setae of theposterior row of the endite of P3, which arefiltratory in other species groups, are modified intorod-like structures resembling the esthetascs of thefirst antenna.We conclude that the filter chamber in the familiesstudied here combines a sensory and a glandularfunction with the filtratory one. These functions,typical of a mouth, are localised behind themasticatory apparatus in vertebrates. In theseCladocera, however, they are physically situated infront of the mandibles.     

Subgeneric differentiation within Kurzia (Crustacea: Anomopoda: Chydoridae) and a new species from Central America

The genus Kurzia is divided into two subgenera: Kurzia s. str. and Rostrokurzia n. subg. Subgenus Kurzia includes Kurzia (K.) latissima Kurz, 1874, with a palearctic -, Kurzia (K.) polyspina n. sp. with a neotropic - , and Kurzia (K.) cf. media (Birge, 1879) with a nearctic distribution. Rostrokurzia includes Kurzia (R.) longirostris Daday, 1898 (pantropical distribution), and Kurzia (R.) brevilabris Rajapaksa & Fernando, 1986, from subtropical and tropical Asia. Kurzia latissima Kurz, 1874, from Central Europe is redescribed in detail.     

Fossil remains of an unknown Alona species (Chydoridae, Aloninae) from a high arctic lake in Nordaustlandet (Svalbard) in relation to glaciation and Holocene environmental history

We analyzed a lacustrine sediment core covering the Holocene from Lake Einstaken, Nordaustlandet, for its fossil Cladocera (Crustacea) with an aim to reconstruct past aquatic communities in this environmentally extreme and unexplored region. In the analysis, we encountered remains (carapaces, ephippia, headshields, and postabdomens) of an unknown chydorid (Chydoridae, Aloninae) species during two separate periods in the early Holocene. The remains had some comparable morphological characters with the European Alona guttata s.str. Sars, 1862 and with the glacial relict Alona werestschagini Sinev, 1999, but they differed clearly from the previous species; the headshield had broadly rounded rostrum and narrow fornices, the ephippium was heavily pigmented and reticulated, and the postabdomen had convex dorsal and ventral margins. The postabdomen had evidently similar morphology with Alona bergi R?en, 1992, which has been described, although inadequately, from arctic Canada and northern Greenland. We conclude, based on the morphology of the postabdomen, that the unknown remains belong to species closely resembling A. bergi, named here Alona cf. bergi, and assume that the species, whether the true A. bergi or some other cryptic species of the A. guttata group, is a postglacial relict of the high arctic adapted to cold climate. Herewith, we emphasize the need for extensive biogeographical investigations into both fossil and intact specimens of chydorids in the arctic.     

New species in the rheophilous genus Nicsmirnovius Chiambeng & Dumont, 1999 (Branchiopoda: Anomopoda: Chydoridae) and reassignment of Alona eximia Kiser, 1948 and Alonella fitzpatricki Chien, 1970

A morphological comparison of specimens previously assigned to Alona eximia Kiser, 1948 from tropical Africa, Eastern Asia and the Americas shows that this species-group shares a number of morphological characters on the postabdomen, head pores, first antenna and second and fourth limb that separate them from Alona Baird, 1843 but unite them with Nicsmirnovius Chiambeng & Dumont, 1999. Alonella fitzpatricki Chien, 1970, formerly believed to be a junior synonym of A. eximia, is separated from the latter and assigned to the genus Nicsmirnovius. Two new taxa, from Africa and the Island of Socotra (Yemen) are added to the genus. The relationship between the specialised habitat of these chydorids and their morphology is discussed. The geographic range of all known populations is figured and a key to species is presented.     

On the Taxonomy and Morphology of the Pine Wood Nematode, Bursaphelenchus xylophilus (Steiner &Buhrer 1934) Nickle 1970

During the past 3 yr, nematologists in the United States have found specimens of Bursaphelenchus sp. in the wood of dead and dying pine trees. This nematode-host association resembles a similar interaction reported from Japan where pine trees are being killed by the pine wood nematode. This taxonomic research was conducted to determine if the Japanese pine wood nematode and similar populations in the United States are of the same species. Based upon typical morphological characters of original specimens of Bursaphelenchus xylophilus (Steiner and Buhrer 1934) Nickle 1970 that were rediscovered in the USDA Nematode Collection and genetic crosses among the Japanese and American nematode populations, it was concluded that they are all the same species, B. xylophilus.     

Use of Cellulose Acetate Electrophoresis in the Taxonomy of Steinernematids (Rhabditida,Nematoda)

A steinernematid nematode was isolated from soil samples collected near St. John''s, Newfoundland, Canada. On the basis of its morphometry and RFLPs in ribosomal DNA spacer, it was designated as a new strain, NF, of Steinernema feltiae. Cellulose acetate electrophoresis was used to separate isozymes of eight enzymes in infective juveniles of S. feltiae NF as well as four other isolates: S. feltiae Umeå strain, S. feltiae L1C strain, Steinernema carpocapsae All strain, and Steinernema riobravis TX strain. Based on comparisons of the relative electrophoretic mobilities (μ) of the isozymes, one of the eight enzymes (arginine kinase) yielded zymograms that were distinctive for each of the isolates, except for the Umeå and NF strains of S. feltiae, which had identical banding patterns. Four enzymes (fumarate hydratase, phosphoglucoisomerase, phosphoglucomutase, and 6-phosphogluconate dehydrogenase) yielded isozyme banding patterns that were characteristic for all isolates, except for the L1C and NF strains of S. feltiae, which were identical. Two enzymes (aspartate amino transferase and glycerol-3-phosphate dehydrogenase) yielded zymograms that permitted S. carpocapsae All strain to be discriminated from the other four isolates, while the remaining enzyme (mannose-6-phosphate isomerase) was discriminatory for S. riobravis TX strain. Except for one enzyme, the isozyme banding pattern of the NF isolate of S. feltiae was the same as in the L1C strain, isolated 13 years previously from Newfoundland. Cellulose acetate electrophoresis could prove invaluable for taxonomic identification of isolates of steinernematids, provided that a combination of enzymes is used.     

A hidden species becoming visible: biogeography and ecology of Rhynchotalona latens (Cladocera,Anomopoda, Chydoridae)

Hydrobiologia - A long hidden chydorid (Chydoridae, Cladocera) taxon, first found as fossil specimens and recently redefined as Rhynchotalona latens (Sarmaja-Korjonen et al., Hydrobiologia 436:...     

Morphological Radiation with Reference to the Carapace Valves of the Anomopoda (Crustacea: Cladocera)

Diversity of the carapace valve structure in the Anomopoda (Crustacea: Branchiopoda) is described. We found that transformations of shape, modifications of the surface and valve margins, and thickening or thinning of the valves, take place independently in different families, sometimes resulting in a convergent similarity. The limits of morphological diversity in these features determine the range of adaptive radiation in general form of the group. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Comments on the morphology of Nicsmirnovius eximius (Kiser, 1948) (Aloninae,Anomopoda, Cladocera) in Thailand,with description of its male

The density, diet and habitat use of brown trout (Salmo trutta) and Siberian sculpin (Cottus poecilopus) were studied in the subalpine River Atna in southeastern Norway in the autumn during a six year period (1986–1991). There was an inverse relationship between the density of brown trout and Siberian sculpin. Diet overlap, as indicated by the Schoener index, was high between the two species, ranging between 0.48 and 0.86. Chironomid larvae and other aquatic insects were the most common food items for both species. Brown trout also consumed substantive amounts of surface insects. Siberian sculpin typically occupied sites with finer substrates and greater water depths than brown trout, even though there was considerable overlap in habitat use between the two species. Because the two species shared similar habitats, we suggest that the potential for species interactions exists, particularly at sites where density of sculpin is high.     

Temperature-Dependent Dispersal Strategies of Aphanizomenon ovalisporum (Nostocales, Cyanobacteria): Implications for the Annual Life Cycle

Aphanizomenon ovalisporum is a planktonic nostocalean cyanobacterium with increasing research interest due to its ability to produce the potent cytotoxin cylindrospermopsin and its potential invasiveness under the global warming scenario. The present study provides novel data on the potential dispersal strategies of A. ovalisporum by analyzing the influence of temperature (10–40 °C) on akinete differentiation and cell morphometry in cultures of A. ovalisporum UAM 290 isolated from a Spanish pond. Our results confirmed a temperature-dependent akinete differentiation, with the maximum akinete production reached at 20 °C (15 % of the cells), a low basal production at 25–30 °C (<0.4 % of the cells) and no detectable production at 35 °C. Furthermore, we reported the fragmentation of A. ovalisporum filaments at temperatures of 25 °C and above. Additionally, we observed that the morphology of vegetative cells varied under different temperature scenarios. Indeed, a strong negative correlation was found between temperature and the width, length and biovolume of vegetative cells, whereas akinete dimensions remained stable along the temperature gradient. Therefore, linear regressions between temperature and the cell size parameters are herein presented aiming to facilitate the identification of A. ovalisporum in the field throughout the course of the year. This is the first study evidencing that akinete production is triggered by temperatures between 20 and 25 °C in A. ovalisporum and reporting the existence of filament fragmentation as a potential dispersal strategy of this species. The importance of these findings for understanding the annual life cycle and invasive potential of A. ovalisporum is further discussed herein.     

Paridris Kieffer of the New World (Hymenoptera,Platygastroidea, Platygastridae)

Paridris in the New World is revised (Hymenoptera: Platygastridae). Fifteen species are described, of which 13 are new. Paridris aenea (Ashmead)(Mexico (Tamaulipas) and West Indies south to Bolivia and southern Brazil (Rio de Janeiro state)), Paridris armata Talamas, sp. n. (Venezuela), Paridris convexa Talamas, sp. n. (Costa Rica, Panama), Paridris dnophos Talamas, sp. n. (Mexico (Vera Cruz) south to Bolivia and central Brazil (Goiás)), Paridris gongylos Talamas & Masner, sp. n. (United States: Appalachian Mountains of Virginia, Tennessee, South Carolina), Paridris gorn Talamas & Masner, sp. n. (United States: Ohio south to Alabama, Georgia), Paridris invicta Talamas & Masner, sp. n. (Brazil: São Paulo), Paridris isabelicae Talamas & Masner, sp. n. (Cuba, Dominican Republic), Paridris lemete Talamas & Masner, sp. n. (Puerto Rico), Paridris minor Talamas, sp. n. (Cuba), Paridris nayakorum Talamas, sp. n. (Costa Rica), Paridris pallipes (Ashmead)(southeastern Canada, United States south to Costa Rica, also Brazil (São Paulo), Paridris psydrax Talamas & Masner, sp. n. (Argentina, Mexico, Paraguay, United States, Venezuela), Paridris saurotos Talamas, sp. n. (Jamaica), Paridris soucouyant Talamas & Masner, sp. n. (Colombia, Trinidad and Tobago, Venezuela). Paridris brevipennis Fouts, Paridris laeviceps (Ashmead), and Paridris nigricornis (Fouts) are treated as junior synonyms of Paridris pallipes; Paridris opaca is transferred to Probaryconus. Lectotypes are designated for Idris aenea Ashmead and Caloteleia aenea Ashmead.     

Relative DNA Content and Chromosomal Relationships of some Meloidogyne, Heterodera, and Meloidodera spp. (Nematoda: Heteroderidae)

The relative DNA content of hypodermal nuclei of preparasitic, 2nd-stage larvae was determined cytophotometrically in 19 populations belonging to 13 species of Meloidogyne, Heterodera and Meloidodera. In Meloidogyne hapla, M. arenaria, M. incognita and M. javanica, total DNA content per nucleus is proportional to their chromosome number, indicating that chromosomal forms with high chromosome numbers are truly polyploid. M. graminicola, M. grarninis and M. ottersoni have a DNA content per chromosome significantly lower than that of the other Meloidogyne species. Within Heterodera, species with high chromosome numbers have proportionally higher DNA content, indicating again polyploidy. DNA content per chromosome in Meloidogyne is one third that of Heterodera and one haft that of Meloidodera floridensis. The karyotypic relationships of the three genera are still not clearly understood.     

Reproductive Stage of the Life Cycle in the Rhizocephalan Barnacle Polyascus polygenea (Crustacea: Cirripedia)

The specific features of the reproductive stage of the life cycle have been studied in the rhizocephalan barnacle Polyascus polygenea, a parasite of the coastal crab Hemigrapsus sanguineus. It is shown that a single crab can bear 1 to 8 externae of P. polygenea. The fecundity of the parasite depends on the size of the externae and their number on the host and may reach as much as 50000 eggs for one externa. In Peter the Great Bay, Sea of Japan, this species repeatedly reproduces during the entire spring–autumn period; externae with developing embryos in the mantle cavity occur from May to September, and planktonic larvae occur from June to October. One externa produces during the season of reproduction no less than three generations of larvae. Thus, the reproductive strategy in P. polygenea comprises a three-stage cascade of reproduction: asexual reproduction via budding of the interna; the development of several generations of one or several externae; and several reproduction cycles of each externa. This allows the parasite to produce a very great number of larvae and ensures the parasitization of a significant proportion of the host crab population. The structure of the ovaries and oogenesis in rhizocephalans and free-living cirripede barnacles have many common features, which provides evidence for integration of these two groups within one monophyletic taxon.